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Biomedical subjects

Tetsuya Sato

Publications and source records attributed to Tetsuya Sato.

At least 19 recordsLinked to original sources
PubMed2006

Atrial fibrillation with hyperthyroidism in a 14-year-old male.

Atrial fibrillation is an uncommon feature of hyperthyroidism in childhood. We report a 14-year-old male who was referred to our hospital with hyperthyroidism and atrial fibrillation. He had a family history of atrial fibrillation. Spontaneous conversion of atrial fibrillation to sinus rhythm occurred 20 weeks after achieving euthyroid state by an antithyroid agent and a beta-blocker. Atrial fibrillation reoccurred after reduction of antithyroid medication and persisted for 19 weeks. Successful electrical cardioversion was performed resulting in conversion of heart rhythm to sinus. Usually, hyperthyroidism associated atrial fibrillation spontaneously reverts to sinus rhythm several weeks after achieving a euthyroid state. Control of thyroid function and heart rate is the goal of therapy for this type of atrial fibrillation.

Adolescent↗
PubMed2006

Partial correlation coefficient between distance matrices as a new indicator of protein-protein interactions.

MOTIVATION: The computational prediction of protein-protein interactions is currently a major issue in bioinformatics. Recently, a variety of co-evolution-based methods have been investigated toward this goal. In this study, we introduced a partial correlation coefficient as a new measure for the degree of co-evolution between proteins, and proposed its use to predict protein-protein interactions. RESULTS: The accuracy of the prediction by the proposed method was compared with those of the original mirror tree method and the projection method previously developed by our group. We found that the partial correlation coefficient effectively reduces the number of false positives, as compared with other methods, although the number of false negatives increased in the prediction by the partial correlation coefficient. AVAILABILITY: The R script for the prediction of protein-protein interactions reported in this manuscript is available at http://timpani.genome.ad.jp/~parco/

Amino Acid Sequence↗
PubMed2006

An 84-year-old patient with an atrial septal defect rescued using the Amplatzer septal occluder device.

We report the case of a rescued 84-year-old patient with atrial septal defect (ASD) who was emergently admitted to our intensive care unit with progressive dyspnea requiring mechanical ventilation for severe anoxia and respiratory arrest. She had no history of congenital heart diseases. ECG and chest X-ray revealed overload of the right atrium and ventricle, and severe increase in pulmonary vascular markings. Transesophageal echocardiography showed a moderately large size ASD (18 x 23 mm(2)). Hemodynamic evaluation documented an increase in PA pressure of 37/16 mm Hg and Q(p)/Q(s) of 2.33. Her systemic condition did not improve following diuretics, cathecholamine, and afterload-reducing substances. She required mechanical ventilation for severe hypoxia. She underwent successful closure of the ASD using an Amplatzer septal occluder on day 17. Hemodynamics and findings on chest X-ray dramatically improved after this procedure. She was discharged from the hospital on foot.

Aged, 80 and over↗
PubMed2006

Effects of intraaortic balloon pumping on the angiographic no-reflow phenomenon after percutaneous coronary intervention in patients with anterior myocardial infarction.

BACKGROUND: The effects of intraaortic balloon pumping (IABP) are considered to be a reduction in myocardial oxygen demand because of systolic left ventricular unloading and an increase in coronary blood flow. Although the former effect has been consistently recognized, the latter effect remains controversial. The purpose of this study was to examine the effects of IABP on the angiographic no-reflow phenomenon. METHODS AND RESULTS: The coronary flow velocity pattern of the left anterior descending artery (LAD) was assessed by transthoracic Doppler echocardiography during IABP counterpulsation, and the effects of IABP were compared between angiographic no-reflow and good reflow patients. The study group comprised 17 patients with anterior myocardial infarction who underwent percutaneous coronary intervention and IABP for typical clinical indications. Echocardiographic data were obtained during 2:1 balloon pumping after coronary angioplasty. In the good reflow group (n=9), IABP counterpulsation increased the mean diastolic flow velocity (MDFV) and peak diastolic flow velocity (PDFV) by 56 +/- 32% (p<0.001) and 48 +/- 27% (p<0.001), respectively. In contrast, in the no-reflow group (n=8), IABP only increased the MDFV and PDFV by 19 +/- 33% (p=0.24) and 6 +/- 12% (p=0.22), respectively. Diastolic deceleration time was smaller and the prevalence of systolic retrograde flow was greater in the no-reflow group than in the good reflow group, and IABP affected neither parameter. CONCLUSIONS: IABP had limited effects on LAD flow velocity pattern in patients with the angiographic no-reflow phenomenon.

Aged↗
PubMed2006

[Takotsubo cardiomyopathy manifesting as no reflow pattern in coronary flow by transthoracic Doppler echocardiography and prolonged recovery of regional left ventricular wall motion abnormality: a case report].

A 80-year-old woman was admitted to our hospital because of chest pain. Electrocardiography revealed ST segment elevation in the I, aVL, and V1-V5 leads. Echocardiography revealed left ventricular apical aneurysmal change with ejection fraction of 31%. Coronary angiography showed no abnormalities. Creatine kinase was not elevated in her clinical course. The diagnosis was takotsubo cardiomyopathy. Transthoracic Doppler echocardiography was performed on the 2nd hospital day. Coronary flow velocity pattern in the left anterior descending artery revealed shortened diastolic deceleration time (108 msec) and systolic retrograde flow. Asynergy of the left ventricle gradually improved, but still persisted slightly at 6 months after discharge. Most patients with takotsubo cardiomyopathy have normal coronary flow velocity pattern in the acute phase. In this case, no reflow pattern of coronary flow was observed during prolonged recovery from left ventricular regional wall motion abnormality.

Aged, 80 and over↗
PubMed2005

Distinct seasonality of depressive episodes differentiates unipolar depressive patients with and without depressive mixed states.

BACKGROUND: The bipolar nature of unipolar depression with depressive mixed states (DMX) needs further validation studies. The seasonality of depressive episodes is indicated to be different between unipolar and bipolar depressions. We therefore explored the seasonal pattern of depressive episodes in unipolar depressive patients with DMX. METHODS: The subjects were 958 consecutive depressive inpatients for a 6-year period. For defining DMX, previously validated operational criteria were used (2 or more of 8 manic or mania-related symptoms: flight of idea, logorrhea, aggression, excessive social contact, increased drive, irritability, racing thoughts, and distractibility). Onsets of the index depressive episodes during each of the 12 calendar months were summed up over the 6-year for bipolar depressive patients (N = 95), and unipolar depressive patients with (N = 77) and without DMX (N = 786) separately. An appropriate statistic was used for testing seasonality. RESULTS: A significant seasonal variation with a large peak in spring was recognized in unipolar depression without DMX, while both bipolar depression and unipolar depression with DMX had a significant fall peak. The monthly distribution of depressive episodes was significantly different between unipolar depression without DMX and other 2 diagnostic categories. Similar results were obtained in separate analyses for each gender. LIMITATIONS: Further replication study using an epidemiological or outpatient sample is needed. Bipolar I and II patients were combined due to a small number of bipolar II patients in this sample. CONCLUSION: Unipolar depression with DMX has a seasonal pattern similar to bipolar depression. The finding provides further evidence of the bipolar nature of unipolar depression with DMX.

Adult↗
PubMed2005

The inference of protein-protein interactions by co-evolutionary analysis is improved by excluding the information about the phylogenetic relationships.

MOTIVATION: The prediction of protein-protein interactions is currently an important issue in bioinformatics. The mirror tree method uses evolutionary information to predict protein-protein interactions. However, it has been recognized that predictions by the mirror tree method lead to many false positives. The incentive of our study was to solve this problem by improving the method of extracting the co-evolutionary information regarding the protein pairs. RESULTS: We developed a novel method to predict protein-protein interactions from co-evolutionary information in the framework of the mirror tree method. The originality is the use of the projection operator to exclude the information about the phylogenetic relationships among the source organisms from the distance matrix. Each distance matrix was transformed into a vector for the operation. The vector is referred to as a 'phylogenetic vector'. We have proposed three ways to extract the phylogenetic information: (1) using the 16S rRNA from the same source organisms as the proteins under consideration, (2) averaging the phylogenetic vectors and (3) analyzing the principal components of the phylogenetic vectors. We examined the performance of the proposed methods to predict interacting protein pairs from Escherichia coli, using experimentally verified data. Our method was successful, and it drastically reduced the number of false positives in the prediction. AVAILABILITY: The R script for the prediction of protein-protein interactions reported in this manuscript is available at http://timpani.genome.ad.jp/~proj/ CONTACT: sato@kuicr.kyoto-u.ac.jp SUPPLEMENTARY INFORMATION: The information is also available at the same site as the R script.

Algorithms↗
PubMed2004

Psychopathology of early-onset versus late-onset schizophrenia revisited: an observation of 473 neuroleptic-naive patients before and after first-admission treatments.

Reports of potential differences in psychopathological presentations between early and late-onset schizophrenia have been controversial. However, such differences in first-episode neuroleptic-naive schizophrenic patients have not been discussed. The authors evaluated symptom profiles in 473 neuroleptic-naive schizophrenic patients before and after first-admission treatments. Both before and after treatment, (1) late-onset schizophrenia had a lower score on affective flattening/social withdrawal than did the earlier-onset counterpart of the illness, even after controlling for potential secondary sources of negative symptoms; (2) systematic persecutory delusion was more severe in patients with late-onset schizophrenia; and (3) the overall effect of age of onset on the psychopathological presentations was greater than the gender-related effects, including the interaction between age of onset and gender. Consideration of late-onset schizophrenia may be important in order to develop an etiologically and clinically reasonable conceptualization of the subtypes of schizophrenia. A factor-analytical study that attempts to compare directly the structure of broad psychopathological presentations in early and late-onset schizophrenia may be a reasonable approach to investigate the longstanding unsolved controversy as to whether or not the neurobiological backgrounds underlying the psychopathological presentations are comparable.

Adult↗
PubMed2004

Mixed depressive features predict maniform switch during treatment of depression in bipolar I disorder.

BACKGROUND: Case observations imply that depressed patients with mixed features are of high risk for maniform switch during acute treatment. METHODS: The medical records of 158 bipolar I depressives were examined with respect to mixed depressive features at admission, naturalistic medications, and maniform switch during inpatient treatment. RESULTS: Besides pharmacological variables, the number of mixed depressive symptoms (flight of ideas, racing thoughts, logorrhea, aggression, excessive social contact, increased drive, irritability, and distractibility) at admission was associated with a higher risk for, and the acceleration of, maniform switch during inpatient treatment. LIMITATIONS: This was a retrospective study in patients receiving naturalistic treatment. The cohort was hospital based and thus not representative of the full range of bipolar affective disorder. CONCLUSIONS: In line with recent studies, our results underline the factors inherent in subjects at a higher risk of switch. Investigation of the relationships between several inherent factors and their interactions with pharmacological treatments may be important in resolving the controversy surrounding antidepressant-induced mania. Further validation studies on mixed depression are warranted.

Bipolar Disorder↗
PubMed2004

Evaluating the inter-episode stability of depressive mixed states.

BACKGROUND: Depressive mixed state (DMX) is understudied, although this diagnostic concept may be of clinical and theoretical importance. Our goal was to provide preliminary evidence of the inter-episode stability of DMX. The inter-episode stability is known to be an important validator for establishing a distinct clinical entity. METHODS: Out of depressive patients consecutively hospitalized at our institute, those who experienced two or more hospitalizations due to discrete depressive recurrences during a 6-year period were selected. All depressive episodes were directly observed and assessed using a standardized rating instrument in terms of eight intra-episode manic symptoms (flight of idea, logorrhea, aggression, excessive social contact, increased drive, irritability, racing thoughts, and distractibility). Assessments for subsequent episodes were performed blindly to those for previous episodes within each patient. RESULTS: The inter-episode stability of categorical DMX diagnoses and the number of intra-episode manic symptoms was moderate but significantly high. Approximately 50% of patients with DMX in the index episode obtained a DMX diagnosis in the second episode. Approximately 40% of the total variance of the number of intra-episode manic symptoms was explained by agreements across several depressive episodes. Depressive patients who experienced a diagnostic switch from unipolar to bipolar disorder had a higher frequency of DMX and a greater number of intra-episode manic symptoms in the index as well as subsequent episodes. LIMITATIONS: All consecutive patients were not followed up. Bipolar I and II patients were combined due to a small number of bipolar II patients in this sample. CONCLUSION: The inter-episode stability of DMX may not be so high as is required for establishing a distinct clinical entity. However, the findings strongly suggest that some depressive patients have a long-lasting liability to DMX. It is important to determine whether such a liability to DMX is mediated by affective temperaments, as was originally hypothesized by Akiskal [J. Clin. Psychopharmacol. 16 (1996) 4S-14S]. DMX may be a risk factor to the diagnostic switch from unipolar to bipolar disorder.

Adult↗
PubMed2003

Genetic variations in tryptophan hydroxylase in suicidal behavior: analysis and meta-analysis.

BACKGROUND: Neurobiological studies implicate serotonergic dysfunction in suicidal behavior. Tryptophan hydroxylase (TPH), the rate-limiting enzyme in the biosynthesis of serotonin, plays a vital role in serotonin metabolism. Thus, variations in the TPH gene have been regarded as prime candidates in the susceptibility to suicidal behavior. The most widely studied genetic variations in the TPH gene, which are located in intron 7, yielded conflicting results in individual studies on suicide-related behavior. METHODS: We performed a meta-analysis on a total of 898 patients and 1179 control subjects, in addition to our local association study in consecutively recruited suicide attempters (n=147) and healthy control subjects of German descent (n=326). RESULTS: We observed a nonsignificant higher frequency of the TPH intron 7 A218 allele in our local group. The meta-analysis showed a weak yet highly significant increase in the frequency of the A218 allele (odds ratio [OR]: 1.33; 95% confidence interval [CI]: 1.17-1.50; p=.00002) and an over-representation of A-carriers (OR: 1.48; 95% CI: 1.22-1.79; p=.00005) in Caucasian suicide attempters/victims. CONCLUSIONS: Our meta-analysis provides strong evidence for an association of suicide-related behavior with an A218 single-nucleotide polymorphism in the TPH gene in Caucasians. Because this variation do not seem to alter functional properties of the TPH gene or protein, functional variations remain to be identified and subsequently tested for association with suicide-related behavior.

Adult↗